The Curse of Humanity
by Oolon Colluphid
Summary: When a portal accidentally opens to a thousand years in the future, a prodigious scientist discovers the demise of humanity, and tries to rebuild it, regardless of the negative consequences. Now, it's up to the rest of Ooo to defeat its creators. AU. Includes Fubblegum and Marceline x Flame Princess. Rated T for violence and whatever else you would like to nitpick.
1. Chapter 1

The Curse of Humanity

Part 1

_____I do not happen to own Adventure Time. If I did, LSP would be fully converted to comic relief._

* * *

Before anyone asks, yes, this chapter is a modified version of Time, Space and Chaos Part 1 from Fubblegum: The Gained Years. I felt like the original was too rushed, s I've separated the two stories, with the other as a failed attempt and this as the proper one. I'll establish the AU in another story, as I am separating my plan for F:tGY into several multi-chaptered stand-alone stories.

* * *

_Prologue (1020 years earlier):_

In the infinite cosmic bubble bath was a Universe. In this Universe was a large spiral galaxy. In this galaxy was a yellow main sequence star. Orbiting this yellow main sequence star were four rocky planets and four gas giants, as well as several other objects. One of the rocky planets had an atmosphere composed mainly of nitrogen, and a surface mostly covered by some form of dihydrogen oxide. The planet's tectonic plates divided the silicon based land formations into continents. On one of these continents was a political constituency called the United States of America. This was further subdivided into fifty states. In one of these was a town called Langley. In Langley, there lived a seventeen-year-old carbon-based ape-cousin named Ben.

Ben was known as one of the most intelligent people in the US (as the United States were abbreviated), having mastered multiple forms of physics, a firm grasp of molecular and cell biology as well as chemistry two years prior. Now, he was holed up in his lab, building a device that looked like an oversized gun, which was effectively what it was. The device's barrel was aimed at a large, eighteen-inch thick round chunk of vanadium steel propped up against the concrete wall of the underground bunker-lab.

"It's finished!" Exclaimed the scientist.

"Finally! How long has it taken you? Five months?" Said someone behind him.

"Six. And anyway, you have it easy, Pen."

"Is it really my fault that I'm good ad geography?"

"Shut up."

The person yawned and stepped out of the shadows. He was about nineteen years old, blond haired, blue eyed and slightly muscled. He was known as an expert in several martial arts and swordfighting practices, and was rumoured to be a knife thrower. However, he was also infamous for being a dreamer. But, his dreams were more than just dreams. As he would soon discover, they stimulated a dimensional wormhole, transferring his consciousness the future, where his body would inexplicably follow. He looked towards the steel plate, and asked how the machine worked.

"Well, we've known that antimatter annihilates 'real' matter when they come in contact," stated Ben, "but what about Dark Matter?"

"How do you get your hands on Dark Matter?" enquired Pen, skeptically, "We don't even know how to find it!"

"I just used an experimental teleport system linked to the vacuum of space, which is now contained in that steel cylinder." He gestured to the steel mass.

"Okay. What are you going to do?" Asked Pen, his voice laced with sarcasm, "Seal off the room, lead line it, cover it in steel and fire the antimatter?"

"Exactly. I had lead lining and several inches of steel plating installed in the walls earlier." Stated Ben matter-of-factly.

Pen groaned, found a chair, laid back and waited for Ben to seal off the room. Then, something caught his attention. Ben was usually a neat freak, and his appearance showed it, wearing almost impossibly clean shirts and trousers, as well as neatly combed hair and a calm demeanour. Now, it seemed the exact opposite, with clothes that didn't seem to have been changed for months, and unkempt hair and a sense of eccentricity. As far as he was concerned, that meant business. And when Ben got serious, the final product was almost guaranteed to work.

After the sealing operation was complete, Ben checked the seal, vacuumed the room, and made sure his equipment was in order, before making a dramatic countdown.

"Firing sequence initiated. Projectile will launch in T minus ten seconds. T minus five, four, three, two, one!"

As soon as he said that, the charge reversed particles slammed into the steel, causing massive explosions as a stray positron collided into a Dark Matter WIMP. All of a sudden, the process seemed to repeat itself over and over again, whilst the room appeared to enlarge and shrink over and over. Pen was the first to comment.

"Oh, great!" Moaned Pen, "Now, you've punched a hole in the fabric of space-time!"

"Look, it's stabilised now, okay?"

Pen grumbled as Ben checked the video feed.

"Hey, look at this!"

"What?"

"It looks like real land over there!" Ben practically screamed.

"Where?" Pen started to gain significant interest.

"Through that portal thingy that the hole opened up!"

"Check the readings."

"The atmospheric consistency is within 0.01% that of Earth's, Air pressure is the same, and the probe says that the gravity is about 5% lower."

"Does the probe have a camera and manual control?"

"Yeah."

"Good. Give it to me."

What Pen saw was astounding. Giant mountains of pure ice gleamed in the distance as the small robot rolled over an endless grassland. What caught his eye were two blobs on either side. He focused on one, and saw an igneous rock formation covered in lava and fire, resembling some sort of building. On the other side was a castle of pink and purple with two giant gumball machines on either side. Just then, a pale blue bearded man in cobalt blue robes flew past past clutching a penguin, pursued by a blond-haired boy of about eighteen wearing black shoes, dark blue shorts and a cyan T-shirt with what appeared to be a white bearskin hat sewn onto the back of the collar to make a makeshift hoodie. He was holding an engraved steel sword with a gold hilt with an emerald set into the pommel and sapphires at the ends of the guard. A crimson sword with a tooth in the pommel and a Celtic cross as the hilt design was strapped to his back. Behind him was a girl, about the same age, with similar attire in pink and magenta, as were her body and hair. Her hair was tied in a ponytail, and she held a sword similar to that of the boy's except with round, cyan pearls set into the guard and pommel. The girl seemed familiar, but before Pen could pin down who she was, the boy's sword flew to the probe and sliced through the battery bank. Just before the camera shorted out, an eighteen year old burning girl hurled a fireball at the old man.

Pen told Ben to do something else whilst he comprehended the situation. He was sure that the blue wizard thingy was the Ice King, and that the pink girl was obviously some sort of Candy Person, but he was certain that he had never seen her before. He checked the time. It was half past nine. Ben would have been in bed by then. Pen opened the now-unsealed door, and walked to the portal. He did the cliché act of moving his hand through the portal. Suddenly, his hand went pale, and this spread everywhere almost instantly. His jaw dropped, which was just as well, as fangs popped out of his upper jaw almost instantly. He ran up to the mirror, and found no reflection. Then came the flashback.

* * *

_**Flashback**_

_ Pen and Marceline were in her riverside house in the cave._

_ "Come on, Marcie!" Whined the eighteen year old adventurer._

_ "What?" Whined the Vampire Queen in a jokingly similar matter_

_"You said you were going to turn me today."_

_"You realise what you're sacrif..." began Marceline, but Pen cut her off._

_"You don't fool me. I heard you when you said that you don't turn people because you'd hate to be stuck with them for eternity."_

_"And what makes you think that you would be an exception?" Said Marceline slyly._

_"Because you love me."_

_Marceline sighed. "You win."_

_ And with that, she bit into his neck, as gently as she could to ease any pain that she might cause. Pen let out a brief ecstatic moan before drifting into unconsciousness._

_**Flashback End**_

* * *

"So, I was right. Ooo is just beyond that portal." He spent about half an hour regaining his bearings, and decided to return to his house. He left a note and floated back to his room through the window.

"I forgot how fun this was." He got a green bag and put in three swords, some "magic" items, an assortment of throwing blades and a few apples, and zipped up the bag. He floated over to the corner where he kept his guitar, and removed most of the body, revealing the demon blood axe-head underneath. He was never sure why they appeared, but they did, so he might as well take advantage of them. Placing the items by the window, he floated over the bed in an attempt at sleeping. Keyword: _attempt_.

Pen spent fifteen minutes rolling over, feeling somewhat empty without Marceline next to him. He heard rumours that if a vaampire turned somone out of piy or ove, then the turned one would have After a frustrated yell, he picked up the axe guitar and green bag, and floated back to Ben's lab. As he floated over, he saw a small group of armoured men with an assortment of guns, including SPAS 12's, MP5's, Glock 18's and even a few M4A1's. They seemed to be creeping slowly towards Ben's lab. He sped up, and reached the door, giving the gunmen an estimated fifteen minutes away before they arrived at slow speed, five if they ran. After knocking several times, Ben opened the door, and almost let out a feminine scream.

"Pen! What the hell happened to you? Did you dye your hair black or something?"

"Never mind that. Just get whatever stuff you want through the portal. Now!"

"What are you talking about?"

"There's guys with guns five minutes away. If you want to live, get through that portal. Don't worry. I've been there before."

"I don't…"

"Just do it!"

The two quickly loaded up a crate with food, a knife, some camping equipment, a magnum and two boxes of ammunition, then shoved it in the portal room and locked the door behind them. Pen then shoved Ben through with the crate, then himself, before the portal collapsed due to logic and physics regaining their place in the Universe after the hole was patched up.

* * *

_Meanwhile, outside the Candy Kingdom…_

Finn placed a foot over the defeated Ice King's head, holding his crown in his left hand whilst a sword pointed menacingly at the old man's neck was held in his right.

"Can't you tell that my sister isn't interested?"Started a bored Finn, "you've tried to kidnap her five times this week."

"If you try that one more time," continued a certain flame princess, "I'll shave your beard of with the hottest flames I can muster, then dump your crown in the deepest lava pit of the Fire Kingdom."

"Nonononono!" stuttered the Ice King, "Isolemnlyswearnevertokidnapyouagain!"

"Alright then, Ice King." Said Princess Bubblegum, who looked over to her half-human boyfriend, cocking her head to gesture to the castle. Finn nodded, and the two took the long trek back, whilst Flame Princess returned to her and Finn's "Tree Fort Mk. 2". After Jake had tried to kill the both of them due to his duties as a COHP member, they had built a secret Tree Fort in case Jake would come back. So far, he hadn't, but as the old saying goes, "better safe than sorry." When she first met Jake, she quite liked him. He seemed to have a kind heart, and certainly seemed very trustworthy, but as time went on, he started acting more and more suspicious , until he finally snapped. _Damned shame, really. He was never that bad. I wonder why he changed._ That thought rang through her head even as she was drifting off onto sleep that night.


	2. Chapter 2

The Curse of Humanity

Chapter 2

Having been abruptly shoved through a portal to a thousand years in the future, Ben was, understandably, confused.

"What happened to you?" He asked, with the question addressed to Pen.

"Well, I'm a vampire here." Said Pen nonchalantly.

Ben started to think Pen was off his rocker, or at least less sane than he was before, which, needless to say, was not very much.

"And where exactly is _here?_" He inquired.

"It's not so much a question of where, so much as a question of _when._" Replied Pen.

Ben was still sceptical. "Tell me more."

Pen complied, and explained the Mushroom War.

"Basically, a thousand years ago, a nuclear and biological war took place on Earth, destroying almost all of humanity and civilisation. This is what it made."

"It doesn't look that bad."

"It's a shame that we can't wait until sunrise." Said Pen, with a hint of nostalgic joy in his voice. "This place is beautiful."

"Burning in the sun, I see."

"Yep."

Ben suddenly remembered what Pen had said a mere three sentences earlier.

"Did you say that most of humanity is gone?" Something snapped in Ben. A primal, pedantic, purist, preservational part of his conscience seemed to whisper "_Dead. Dead. Dead."_ over and overlike Emperor Palpatine. Ben shook it off.

"Anyway," interjected Pen, breaking Ben's trance. "We need to get some info on when we are. Princess Bubblegum should know about that. She's that way." Added Pen, pointing to a large pink castle in the distance. "She may be the second to last person I want to meet right now, but she's our only reliable source."

Ben was slightly puzzled by Pen's use of 'second to last'. "_Second_ to last? Who's _the_ last, then?"

Pen replied in such an heartfelt and guilty way that he might have prompted even the most objective judge to take pity on him. "My girlfriend."

* * *

_At the Tree Fort Mk.2:_

Flame Princess swallowed a small lump of coal, bored completely out of her mind. In her state of boredom, she looked out her window. Dark grey clouds formed and clustered into a thick blanket of cotton-like darkness. _No hope of going out now._ She sighed and lay down on the bear fur sofa, staring absent-mindedly at the ceiling. Then came a tap, followed by a whack, and then a twang, each one coming faster than the one before. _Knife storm_. Then, a different sound came. A distinct ring resounded from the door. Rolling off the soft cushions, she floated down to the door, not wanting to use her legs, and opened it to see a certain cloaked vampire queen. There was a small cut on her arm, with some thin black liquid seeping out of it.

"Hi, Kenna!" Said Marceline, with a tinge of embarrassment.

Flame Princess smiled a bit at the use of her real name. "Need somewhere to stay 'till the storm passes?"

"Yep."

Kenna unblocked the doorway and gestured inside with her thumb.

Marceline removed her cloak and made her way to the soft fur sofa.

"Oh, no, you don't! You are _not_ bleeding all over my couch!"

Marceline looked at where the cut was. "It's healed up now. Don't worry, Ken."

An irritated voice yelled back. "And don't call me Ken! It makes me sound like some gay doll!"

"Like we're any different." Chuckled Marceline. Having been awake for much of the night before performing at a club, she soon drifted off into sleep.

* * *

_In a city 1020 years ago:_

A young girl of about seven wandered around a park, remaining in the shade as much as she could, glaring at the children, especially those with parents nearby. _Lucky them. They have parents who care. Mom… Why did she have to die? Stupid priest trying to "exercise" me or something…_

Behind her came a snobbish voice. "Hey, Demon Girl! Lost your mom as well?"

The words hit her like a Pan Galactic Gargle Blaster. How dare he insult her mother! She knew he was stronger, so she did the only thing she could. She ran. Buildings and pedestrians seemed to whizz past as she bolted through the streets, trying to find another place to stay. As she sped along the pavement, she could still hear the voice behind her. "Demon Girl has no parents!" _Why am I so obsessed over a bully?_ She didn't care. She shot through the city as far as her little legs could carry her. A friend of her mother's found the next day. He intended to leave town, and she left with him, unaware that the planes that would soon fly above them weren't theirs.

Then it came. A bright flash of light came from behind, forming into a huge fiery fist emerging from the ground, crushing hopes, dreams and lives in one fell swoop. However, the city would not be fully destroyed. Deep down beneath the annihilated surface, a number of children and adults alike were frozen to be revived once the conflict was over. Unfortunately for a certain sadistic boy, that revival wouldn't last very long.


End file.
